The present application claims priority under 35 U.S.C. xc2xa7119 to Japanese Patent Application No. 2000-051120, filed Feb. 28, 2000, entitled xe2x80x9cMATERIAL FOR MEASURING STATIC AND DYNAMIC PHYSICAL PARAMETERSxe2x80x9d. The contents of this application are incorporated herein by reference in their entirety.
1. Field of the Invention
The present invention relates to a material used as a sensor that configures a sensor for measuring a static and dynamic physical parameter such as force, pressure, torque, speed, acceleration, position, displacement, impact force, weight and mass, degree of vacuum, rotational force, vibration or noise.
2. Related Arts
Conventionally, there has been known a semiconductor silicon single crystal and silicon carbide or the like as a constituent material for a sensor that can measure a static and dynamic physical parameter such as force, pressure, torque, speed, acceleration, position, displacement, impact force, weight and mass, degree of vacuum, rotational force, vibration or noise, via a distortion (stress), that is, a material having a piezoresistance.
In addition, as a piezoresistance material, there is also known La1xe2x88x92xSrxMnO3 or the like that is a pervskite type composite oxide.
The piezoresistance used here denotes a phenomenon in which, when a compression stress, a tensile stress, a shear stress, or static hydraulic stress are applied to a material, an electrical resistance of a material changes.
However, a conventional material is low in mechanical strength, and thus, has been hardly used as a constituent element of a sensor used for measurement under a high pressure and a high load. Therefore, a material for measuring physical parameters made of such a conventional material has been subjected to measurement under a high pressure and a high load by putting it in a proper pressure resistance container.
Thus, there has been a problem with a complicated sensor construction and higher cost.
It is an object of the present invention to provide a sensor material for measuring physical parameters capable of configuring a sensor capable of directly measuring a high value of physical parameters such as high stress or high pressure without employing a pressure resistance container.
According to one aspect of the invention, the sensor material for measuring static and dynamic physical parameters includes a matrix made of an electrically insulating ceramic material, and piezoresistance materials which are dispersed in the matrix so as to be electrically continuous to each other.